Manufacturing ERP Software
Categories: Problem Solving
Problem Solving in Manufacturing: The Systems Thinking Tools, Part 1

Problem Solving in Manufacturing: The Systems Thinking Tools, Part 1

By Bob Sproull

This is the first post in a new series on a Theory of Constraints (TOC)-based set of “systems thinking tools.” In this series, I will explain these logic-based tools and demonstrate how each can be used in isolation or as a group to solve simple and complex problems. I will focus on the first tool, the current reality tree (CRT) because it will be the most useful for you to use.

Much of what is presented in this series is taken from the book, Epiphanized: A Novel on Unifying Theory of Constraints, Lean, and Six Sigma, Second Edition by Bob Sproull and Bruce Nelson, CRC Press, Taylor and Francis Group, 2015.

Systems Thinking

So just what is “systems thinking”? In simple terms, this is the process of understanding just how things regarded as systems might influence one another. In nature, systems thinking might include an ecosystem in which various elements such as air, water, plants, and animals work together to either survive or die. As a business management discipline, systems thinking is concerned with examining the basic linkages and interactions between the individual components that comprise the totality of the defined system.

The systems thinking tools I will present and discuss were developed and popularized by Dr. Eliyhau Goldratt, the creator of the Theory of Constraints. These thinking tools are a series of visual documentation diagrams which use simple logic to capture your thinking as you move through the various analysis tools. One of the major benefits of these tools is that they can be used individually to help isolate and solve a specific problem or they can be used in sequence to conduct a full systems analysis.

The tools are structured and based on one of two distinctly different types of logic, which are necessity and sufficiency. These tools are powerful in their ability to filter and link the logic, but they are also very time intensive to complete. With this simple overview, it is not my intent to have the reader become proficient in using these tools, but rather to become aware that such tools exist and to gain a basic understanding about what these tools can do and how they work.

There are five major subsets of the systems thinking process tools:

  1. Current reality tree
  2. Conflict resolution diagram (a.k.a. as the evaporating cloud and/or conflict resolution diagram)
  3. Future reality tree
  4. Prerequisite tree
  5. Transition tree

The current reality tree

So, let’s look at the first of these five tools, the current reality tree (CRT). This systems thinking tool is used primarily to study, examine, and document your reality as it exists at a single point in time. It’s a snapshot of a system in its current state. As the name suggests, the CRT defines things as they currently exist. The CRT is a collection of entity statements that are linked together using sufficiency-based logic. Sufficiency-based logic is based on simple “if” and “then” statements and the logic is cause-effect-cause in nature. In other words, if entity A exists, then entity B probably exists. This statement means that entity A is sufficient to cause entity B.

The CRT is typically the tool of choice for defining and logically connecting the current state of activities within a given system. The foundational structure of the CRT is comprised of entities commonly referred to as undesirable effects (UDEs). The UDEs list is populated by asking the question, “In my current reality, what is it that bothers me?” The answer to this question becomes the list of UDEs that exist in your current reality. Usually, a list of five to seven UDEs are required to start your analysis. However, it is possible that more UDEs will be surfaced during the construction of the current reality tree.

In total, these UDEs become the assortment of all the undesirable effects that seem to be happening in the current system at the same time. Each of these negative events might appear to happen in isolation, but in reality, they are events that can be linked together using cause-effect-cause relationships. Using sufficiency logic to determine the cause-effect-cause relationships between events (UDEs) will provide a detailed and clear understanding about why particular events seem to happen over and over again.

Once the CRT is logically connected and verified, it is possible to identify that a single UDE (core problem) near the bottom of the tree is actually creating all of the other UDEs. This is the true value of the current reality tree. If you can identify this single UDE and eliminate it, most, if not all of the other UDEs will disappear.

Coming in the next post

In my next post, we will continue our discussion on the current reality tree, demonstrate how to construct one and then begin discussing the remaining systems thinking tools. 

Until next time,

Bob Sproull

Bob Sproull

About the author

Bob Sproull has helped businesses across the manufacturing spectrum improve their operations for more than 40 years.

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